37 - Outcomes of kidney transplants from toxoplasma IgG positive donors: An Organ Procurement and Transplant Network (OPTN) database analysis

Sunday, April 30, 2023

3:30 PM – 6:00 PM ET

Poster Number: 37
Publication Number: 37.349

Lavjay Butani, University of California Davis, Sacramento, CA, United States; Daniel J. Tancredi, University of California, Davis, School of Medicine, Sacramento, CA, United States

Presenting Author(s)

LB

Lavjay Butani, MD

Professor Of Pediatrics
UC Davis

Background: In the current era, marked by a shortage of organ donors, there is a need to reconsider accepting organs from donors previously considered suboptimal, in the absence of robust evidence-based data. Toxoplasma antibody positive donors (TPD) constitute one such group, due to the risk of disseminated infection after transplantation (Tx).

Objective: To compare graft survival rates in recipients ( < 50 years of age) of deceased donor kidneys, stratified by recipient age (pediatric < 18 years) and Toxoplasma IgG status, using the national OPTN database.

Design/Methods:

A Cox regression model for time to graft failure (graft loss or patient death) categorized by Toxoplasma IgG status and recipient age, statistically adjusting for important confounders (such as HLA mismatch, cause of renal disease, ischemia times etc.) was applied to pediatric and adult recipients age 50 or less of 1^st kidney only transplants, using data from the OPTN database from 2018-2022.

Results: Of the 16533 Tx, 1193 (7.2%) were from TPD; pediatric patients accounted for 1826 Tx (5% were from TPD). Pediatric recipients of TPD organs were more likely to be non-Hispanic black (30.4% versus 22.3%, p 0.05). TPD Tx occurred each year during the study period and in each OPTN region. Similar proportions of TPD Tx and Toxoplasma negative Tx were pre-emptive (about 40%; p 0.82). There were no differences in HLA mismatch between the 2 groups and the incidence of delayed graft function and acute rejection were similar too. For the pediatric patients, there were 70 graft failures/deaths in 2706.74 person years of follow-up among those who were Toxoplasma negative, for a crude rate of 2.58 failures per 100 person-years (95% CI: 2.04, 3.26). For the TPD recipients, there were 4 failures in 143.04 person years of follow up, a crude rate of 2.80 failures per 100 years of follow-up (95% CI: 1.05, 7.45). The crude failure rate ratio was 1.08 (0.39, 2.97) and the adjusted hazard rate ratio was 0.67 (95% CI: 0.23, 1.94). Similarly, for the entire cohort of recipients, the crude failure rate ratio was 1.20 (95% CI: 0.96, 1.49) with the adjusted hazard rate ratio of 1.09 (95% CI: 0.87, 1.36).

Conclusion(s):

In a large cohort of pediatric and adult renal Tx recipients, TPD graft recipients have comparable survival to Tx from Toxoplasma negative recipients. While caution must still be taken and close monitoring of recipients undertaken post-Tx for surveillance of disseminated toxoplasmosis, our study suggests that children and adults can be successfully managed using organs from TPD.